Observing Relative Homotopic Degeneracy Conversions with Circuit Metamaterials.

Making nodal lines (NLs) deterministic is quite challenging because directly probing them requires bulk momentum resolution. Here, based on the general scattering theory, we show that the Bloch modes of the circuit metamaterials can be selectively excited with a proper source. Consequently, the transport measurement for characterizing the circuit band structure is momentum resolved. Facilitated by this bulk resolution, we systematically demonstrate the degeneracy conversions ruled by the relative homotopy, including the conversions between Weyl points (WPs) and NLs, and between NLs. It is experimentally shown that two WPs with opposite chirality in a two-band model surprisingly convert into an NL rather than annihilating. And the multiband anomaly (due to the delicate property) in the NL-to-NL conversions is also observed, which in fact is captured by the non-Abelian relative homotopy. Additionally, the physical effects owing to the conversions, like the Fermi arc connecting NLs and the parallel transport of eigenstates, are discussed as well. Other types of degeneracy conversions, such as those induced by spin-orbit coupling or symmetry breaking, are directly amenable to the proposed circuit platform.

A nomogram for the preoperative estimation of neuroblastoma risk despite inadequate biopsy information.

BACKGROUND AND PURPOSE: If the preoperative pathological information is inadequate, a risk classification may not be able to be determined for some patients with neuroblastoma. Our objectives were to include imaging factors, serum biomarkers, and demographic factors in a nomogram to distinguish high-risk patients before surgical resection based on the COG classification. METHOD: A total of 106 patients were included in the study. Of these, patients with clinicopathologically confirmed neuroblastoma at Tianjin Children's Hospital from January 2013 to November 2021 formed the training cohort (n = 82) for nomogram development, and those patients from January 2010 to December 2013 formed the validation cohort (n = 24) to confirm the model's performance. RESULT: On multivariate analysis of the primary cohort, independent factors for high risk were the presence of distant metastasis (p = 0.004), lactate dehydrogenase (LDH) (p = 0.009), and tumor volume (p = 0.033), which were all selected into the nomogram. The calibration curve for probability showed good agreement between prediction by nomogram and actual observation. The C-index of the nomogram was 0.95 95% [0.916-0.99]. Application of the nomogram in the validation cohort still gave good discrimination and good calibration. CONCLUSION: Three independent factors including the presence of distant metastasis, lactate dehydrogenase (LDH), and tumor volume are associated with high-risk neuroblastoma and selected into the nomogram. The novel nomogram has the flexibility to apply a clinically suitable cutoff to identify high-risk neuroblastoma patients despite inadequate preoperative pathological information. The nomogram can allow these patients to be offered suitable induction chemotherapy regimens and surgical plans. LEVELS OF EVIDENCE: Level III.

Roles of Surgery in the Treatment of Patients With High-Risk Neuroblastoma in the Children Oncology Group Study: A Systematic Review and Meta-Analysis.

Purpose: Neuroblastoma is the most common extracranial solid tumor in children, and most patients are at high risk when they are initially diagnosed. The roles of surgery and induction chemotherapy in patients with high-risk neuroblastoma have been a subject of much controversy and debate. The objective of the current study was to assess the roles of surgery in high-risk neuroblastoma. Method: The review protocol was prospectively registered (PROSPEROID: CRD42021253961). The PubMed, Embase, Cochrane, and CNKI databases were searched from inception to January 2020 with no restrictions on language or publication date. Clinical studies comparing the outcomes of different surgical ranges for the treatment of high-risk neuroblastoma were analyzed. The Mantel-Haenszel method and a random effects model was utilized to calculate the hazard ratio (95% CI). Results: Fourteen studies that assessed 1,915 subjects met the full inclusion criteria. Compared with the gross tumor resection (GTR) group, complete tumor resection (CTR) did not significantly improve the 5-year EFS [p = 1.0; HR = 0.95 (95% CI, 0.87-1.05); I 2 = 0%], and the 5-year OS [p = 0.76; HR = 1.08 (95% CI, 0.80-1.46); I 2 = 0%] of patients. GTR or CTR resection had significantly better 5-year OS [p = 0.45; HR = 0.56 (95% CI, 0.43-0.72); I 2 = 0%] and 5-year EFS [p = 0.15; HR = 0.80 (95% CI, 0.71-0.90); I 2 = 31%] than subtotal tumor resection (STR) or biopsy only; however, both CTR or GTR showed a trend for more intra and post-operative complications compared with the STR or biopsy only [p = 0.37; OR = 1.54 (95% CI, 1.08-2.20); I 2 = 0%]. The EFS of the patients who underwent GTR or CTR at the time of diagnosis and after induction chemotherapy were similar [p = 0.24; HR = 1.53 (95% CI, 0.84-2.77); I 2 = 29%]. Conclusion: For patients with high-risk neuroblastoma, complete tumor resection and gross tumor resection of the primary tumor were related to improved survival, with very limited effects on reducing intraoperative and postoperative complications. It is necessary to design strong chemotherapy regimens to improve the survival rate of advanced patients. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/, PROSPEROID [CRD42021253961].

Liver tumour segmentation using contrast-enhanced multi-detector CT data: performance benchmarking of three semiautomated methods.

OBJECTIVE: Automatic tumour segmentation and volumetry is useful in cancer staging and treatment outcome assessment. This paper presents a performance benchmarking study on liver tumour segmentation for three semiautomatic algorithms: 2D region growing with knowledge-based constraints (A1), 2D voxel classification with propagational learning (A2) and Bayesian rule-based 3D region growing (A3). METHODS: CT data from 30 patients were studied, and 47 liver tumours were isolated and manually segmented by experts to obtain the reference standard. Four datasets with ten tumours were used for algorithm training and the remaining 37 tumours for testing. Three evaluation metrics, relative absolute volume difference (RAVD), volumetric overlap error (VOE) and average symmetric surface distance (ASSD), were computed based on computerised and reference segmentations. RESULTS: A1, A2 and A3 obtained mean/median RAVD scores of 17.93/10.53%, 17.92/9.61% and 34.74/28.75%, mean/median VOEs of 30.47/26.79%, 25.70/22.64% and 39.95/38.54%, and mean/median ASSDs of 2.05/1.41 mm, 1.57/1.15 mm and 4.12/3.41 mm, respectively. For each metric, we obtained significantly lower values of A1 and A2 than A3 (P < 0.01), suggesting that A1 and A2 outperformed A3. CONCLUSIONS: Compared with the reference standard, the overall performance of A1 and A2 is promising. Further development and validation is necessary before reliable tumour segmentation and volumetry can be widely used clinically.

Predictive surgical simulation of aorta reconstruction in cardiac surgery.

This paper proposes a method for performing predictive simulation of complex cardiac surgery. It computes complex surgical results given a small amount of user inputs. In this way, the surgeon can easily explore various surgical options without having to go through all the detailed steps of the surgical procedure. Test results, using aorta reconstruction as an application example, show that the proposed method can generate realistic simulation results given different kinds of user inputs, thus demonstrating the feasibility of the approach.